Telephone system



July 2s, 1931.

A. C. POWELL TELEPHONE SYSTEM Filed Sept. 2k6, 1930 ATTORNEY n Patented July 28. 1931 ALBERT C. POWELL, OF NEW YORK, N. Y.,

PATENT OFFICE ASSIGNORVTO BELL TELEPHONE LABORA- TORIES, INCORPORATED, OF NEW YORK, N. Y.,.A CORPORATION F NEW YORK TELEPHONE SYSTEM Application filed September 26, 1930. Serial No. 484,476.

This invention relates to telephone systems and particularly to arrangements for measuring the use of telephone equipment.

The objects are to increase the etliciency and reliability of apparatus employed for registering the extent to which the equipment is used, to render such apparatus more 20 simultaneously may cause only one operation of the register. Thus a substantial error is introduced in the count due to the fact that the register is not permitted to operateand release with sufficient rapidity to free itself from one calling trunk before the next call appears.

According to the present invention, these ditiiculties are overcome by an arrangement in which the operation of the common counting register is initiated by the operation of a relay individual to Vany trunk ot the group served by the register, whereas the complete operation ot the register is controlled by a local circuit independent of the relay indik vidual to the trunk. In this way, the initiating ,circuit originally closed by the individual trunk relay is immediately opened following the initiation of the register operation so that the register, as soon as it has operated, may again release to be in readiness for a subsequent operation due to a calling condition on some other trunk.

The ldrawing accompanying this speciiical tion discloses a portion of a semi-automatic telephone system involving an originating mechanical oiiice and a terminating manual oiiice. The drawing illustrates three separate operators positions in the manual office to which the various trunks of an incoming '50 `group are 'distributed together with the trunk finding and position control switches.

The calling subscribers lines 1, 2 and 3 terminate in the line inder switches LF 1, LTT-2 and LF-B in the full-mechanical olftice A. These line finder switches are re` spectively coupled to first selector switches S 1, S 2, and S 3. 4The switches S 1, S 2, and S-B have access to trunks T l, T 2, and T S of a group extending to a distant manual terminating otiice. 'The trunk T l is shown terminating in the operators cord circuit- 0 1 at the position 0 1. Trunk T 2 terminates in cordr 0 2 at position 0 2, and trunk T 8 terminates in cord circuit 0 3 at position 0 3. understood, of course, that the arrangement disclosed is merely for illustration. At the originating office, the selector switches are controlled by central oiiice register senders 5, 6 and 7. Lines 1, 2, and 3, for example,-

might all terminate in the same line iinder switch, and trunks T l, T 2 and T S might terminate in the same selector switch.

Trunks incoming to an operators position are served by a number of trunk finder switches each having access to a plurality ot' trunks.` At position 0 1 the trunk inder switches TF 1, TF 2, and T F S'serve to iind the trunks on which calls appear and to extend them to the position and indicating circuits. For each three trunk viinders at position 0 1 there is provided a control switch CS l. In like manner position 0 2 is equipped .with trunk iinders TF 4, TF-, and TF 6 and control switch GS 2, and position 0 3 is similarly equipped with trunk finders TF 7, TF 8 and TE 9 and control switch CS S. f The cords 0 1, 0 2 and 0 3 are respectively equipped with relays 8, 14 and 17. The purpose or' these relays is to disconnect the tip and ring conductors of the` incoming trunks from the plugs of the respective cord circuits and to extend them to the indicating equipment. The position circuits at the-operators positions are respectively equipped with diiiperential relays 9, 15 and 18, the purpose of which will appear hereinafter.

The total number of calls received over a given group of trunks is recorded on a meter It willv be will now be given.

22 provided in common to all trunks of the group.

For a more complete understanding of the detailed operation of the system as a whole, reference is made to the patentV to W. A. Rhodes l1,7i6,795 of February 11, 1980.

A detailed description of vthe operation Assume that ythe subscriber of line 1 Wishes to hold a conversation with the subscriber ofline 23. The initiation of the call results in the operation of line finder LF-l to extend the subscribers line to the selector S-l and to the sender 5. The subscriber manipulates his dial 4L to set up the record of the called number in the register sender 5. Thereupon, the sender controls the switch S-1 and succeeding switches in case these are necessary to extend the connection over a trunk T 1 terminating in the plug 12 of the operators cord'circuit (1 1 atpositicn 0 1. The extension of the connection to the cord circuit C-l results in the operation of trunk i'iiider TF-l to find the calling trunk. As soon as the trunk is selected, the relay 10 operates and completes a circuit from ground through its armature and contact to beth windings of the differential relay 9 to battery. Since the relay 9 is differential, it does not attract its armature at this time.

At a subsequent period in the operation of the system, control switch CS-l completes its preparatory functions and relay 11 operates. Relay l1 completes a circuit from ground through its armature and contact, through the brushes ofCS-l and TF-1 and the Winding of the individual trunk relay 8 to battery. Relay 8 operates and yextends the tip and ring conductors of the trunk T-l over conductors 26 and 27 to the recording and indicating equipment not shown in this drawing. Relay 8 also completes a circuit from Aground through the contact of relay 10, upper Winding of relay 9, normal contact of relay 9, lower contact ofrelay 8, over a common conductor 20 through the Winding of relay 21 and the winding of the register 22 to battery. Relay 21 operates in this circuit, but relay 9 being'differential `still retains its armature in its retractedposition. Relay 21 immediately completes a local circuit froin'battery through the winding of register 22, Winding' of relay 21, con

Vtact of relay 21 to ground. This local circuit insures the complete operation of the register 22 and becomes edective immediately after the registering condition is placed on the common conductor 20. Relay 21 by applying ground potential to the common conductor 20 short circuits the upper winding of the relay 9, permitting the lower winding to operate the armature. Relay `9 at its front contact closes a locking circuit traceable `from battery throughthe lower Winding of the relay, contacts of said relay to ground at the contact of relay l0. Relay 9 also immediately opens the branch circuit extending from the main conductor 20 to the ground of relay 10.

As soon as the register 22 has fully operated and recorded the call, it closes acircuit from battery through its Winding and contact to` ground at the contactofrelay21. This circuit shunts the relay 21, which thereupon releases and opensthe local energizing and holding circuit of the register 22. Register 22 thereupon releases in order to be in readiness for the next call.

By this arrangement the initial energizing circuit, completed over any one of the Vbranches extending from the common conductor20 to the various position circuits, is opened before the register 22 has had a chance to operate and release. This eliminates the danger of overlap due to tWo calls existing simultaneously or nearly so at two different positions.

After the number of the called line V23 has been displayed before the operator, she

seizes the plug 12 and inserts itin the Vjack 1.

1. In combination, a register, an operating circuit for said register comprising a main path and a plurality of branch paths, means for closing one of the branch paths to effect the operation of the register, a relay in the main path responsive to such closure, and means responsive to the operation of said relay for opening the closed vbranch' path;

2. In combination, a register, an operating circuit for said register comprising amain For a detailed explanation of the iio path and a plurality of branch paths, means for closing a first one of said branch paths Y to cause the operation of the register, a relay in the lmain path responsive to such closure, means responsive to said relay for opening said first branch, and means controlled by said relay for causing the immediate release of said register to place the same under control of a second one of said branch paths.

3. In combination, a counting meter, an operating circuit for said meter including a plurality of parallel branches, means for closing one of said branches to initiate the operation of the meter, a relay in theoperating circuit responsive to the closure of one of said branches for causing the complete operation of the meter independent of said branch, `and means controlled by said'relay fer opening a closed branch. i

4. The combination in a registeringsystern of a fcounting register, an operating circuit for said register comprising a plurality of parallel branches, differential relays, one for each of said branches, means for energizing the windings of the relay in a first one of said branches, means for closing said first branch to initiate the operation of said register without actuating said relay, and a relay common to all of said branches for causing lthe complete operation of the register independentief said first branch and for causing the operation of the differential relay associated with said first branch to disconnect such branch from the common register.

5. In combination, a plurality of operators positions, a group of trunks appearing in said positions, a meter common to said trunks, an operating circuit for said meter including a branch for each of said operators positions, means for closing one of the branches to effect the operation of the meter, and means responsive to such closure for removing the meter from control of said first mentioned branch.

6. In combination a group of lines, a meter and a meter control relay common to said lines, a relay individual to each of said lines, a conductor for connecting said meter and control relay to each of said individual relays, means effective in response to the seizure of one of said lines for connecting the corresponding one of the individual relays to said conductor to effect the operation of said con trol relay and said meter, means responsive to the oepration of said control relay for disconnecting said one of the individual re lays from said conductor, and means controlled by said meter for causing the releasel of said control relay to render said control relay responsive to the seizure of another one of? said lines.

7. In combination a group of lines, a meter and a meter control relay common to said lines, a relay individual to each of said lines a circuit closed in consequence of the seizure.` of' one of said lines and including the correspending one of said individual relays for operating said control relay without operating said one of the individual relays, contacts of said control relay for operating said meter and for operating said one of the individual relays, contacts of said one of the individual relays for opening said cir-- cuit, and contacts of said meter for causing the release of said control relay.

S. In combination a group of lines, a meter and a meter control relay common to said. lines, a relay individual to each of said lines, a circuit closed in consequence of the seizure of one of said lines and including the'y corresponding one of said individual relays for operating said control relay without operating said one of the individual relays, a circuit closed by said control relay for operating said meter, a circuit closed by said con trolrelay vfor operatingsaid one of the individual relays,contacts`of saidmeter for causing the release of said controlrelay, and con- :tacts ofsaid; one of the-individual relays for vbpening said circuit for operating said control .relay. p v y n T9. A In `combination a group of trunks, a register andy a register control relay common to.saidtrunksa differential relay individual to each of said trunks, a first circuit closed in iconsequencedof the seizure of one of said trunks throughl both windings of the corresponding one of said individual relays, said Lfirstcircuit being ineffectiveto operate said individual rela, a secondy circuit closed in consequence o n the seizure of said trunk through one winding-'of saidindividual relay gfor operating said control relay, said second -circuit being ineffective to operate said individual relay, circuits closed by said control relay for operating said register and said individual relay, means responsive to the oper- :ationofV said `.individual relay for opening :said second circuit, and means responsive to the operation of said register for causing the release of said control relay. f

10. In combination a group of trunks, a register and a register control relay common Vto said trunks, a differential relay individual to each of said trunks, a first circuit closed in consequence of the seizure of one of said trunks through both windings of the corresponding one of said individual relays, said first circuitfbeing ineffective to operate said y :individual relay, a second circuit closed in consequence of the seizure of said trunk through one winding of said individual relay for operating said control relay, said Second fioo -circuit being ineffective to operate said indi- 1 vidual relay, contacts of said control relay for operating said register and for short-circuiting one windin of said individual relay to cause the operation of said individual relay, means responsive to the operation of said individual relay for opening said second circuit, and means responsive to the operation of said register for causing the release of said control relay.

11. In combination a group of lines, a me- 'ter and a meter control relay common to said lines, a relay individual to each of said lines, .a circuit closed in consequence of the seizure of one of said lines and including the corresponding one of said individual relays for operating said control relay without operating said one of the individual relays, contacts of said control relay for operating said meter :and for operating said one of the individual relays,"contacts of'said one of the individual -relays for opening said circuit, means for holding said one of the individual relays operated, and contacts of said meter for causing the release of said control relay. i

12. In combination a groupv of trunks, a :w

register and a register control relay commonV to s aid trunks, adii'erential relay individual to earch of said triinks, zt first circuit closed in Consequence vofthe seizure of one of .Said trunks through both windings of thecorre- Spending one Qf Seid individual relaysed first circuit being ineffective to operate said individuel relayt` second circuitelosedmin consequence of the seizure Voit said trunk through one ,Windingof seid individualrelay for operating saideontrol relay, said Segond cireuitbeing ineffective toIoperate s aidindividual re1y,',eontaet s of v said control relaj7 for operating said register and-for shortfoir- @uiting one vinding of saidindividillalrelay to canse the Q perationof said individuel I'elay, means responsive yto the operation of said individual relaty kforopvening rseid vsecond cireuit,yineens for holding seid one ofthe individual relays operated, endmeansresponlsive to the operetionof saidregisterforicausing thevrelease of seidcontrol relay.

`In Witness whereof, I hereunto Subscribe myneine this 24th day'of September, y1930. ALBERT C. POWELL. 

